Brake Pressure Calculator

Note: The quantity in stock updates each night at midnight. This doesn't include any orders that we've taken throughout the day.

When selecting brake master cylinders, you'll notice with a smaller bore, you get more pressure but less volume. With a larger bore you get less pressure but more volume. You need to make sure that you have enough volume to supply your brake calipers, but at the same time, enough pressure.

For tandem master cylinder pedal assemblies, offroad trucks and buggies will have more bias to the rear brakes. 60% rear and 40% front is a common starting point, with a lot of offroad racing vehicles ending up at 30% front and 70% rear. Opposite of a street vehicle.

For single master cylinder pedal assemblies, here is an example of the math. Pushing the brake pedal with 100 pounds of force, a 6.25:1 pedal ratio and a single 3/4" bore master cylinder:

Pedal force at master cylinder:
100 lbs x 6.25 ratio = 625 lbs

3/4" master cylinder area:
A = π r2
A = 3.14159 x 0.375 x 0.375
A = 0.4418 in2

Brake line pressure:
625 lbs ÷ 0.4418 in2 ≈ 1415 PSI out of a single brake master cylinder

Single Master Cylinder

Pedal effort in pounds:
Pedal ratio (input as decimal not as fraction 6.25 not 6-1/4):
Master cylinder bore:



Tandem Master Cylinders

Rear bias percentage (percent represents effective force split, not bias bar turns):

Pedal effort in pounds:
Pedal ratio (input as decimal not as fraction 6.25 not 6-1/4):
Front brake master cylinder bore:
Rear brake master cylinder bore:


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